nav {
    font-size: 16px;
    font-family: "微软雅黑";
}
#header {
    background-color: white;
    border-bottom: 2px solid #EEE;
    margin-bottom: 20px;
}
#header > nav{margin-bottom: 0;}
body {background-color: #F9F9F9;}
a {color: #666;}
a:active, a:visited {text-decoration: none;}
a:hover {
    color: lightseagreen;
    text-decoration: none;
}
.nav > li > a:hover {background-color: inherit;}
button {outline: none;}